* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

li {
  list-style: none;
}

.box {
  display: flex;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  background-image: linear-gradient(120deg, #e0c3fc, #8ec5fc 100%);
}

.weapon-box {
  width: 702px;
  height: 208px;
  margin-top: 150px;
  background-color: #fdf9f3;
  padding: 0 11px;
}

.weapon-box .nav {
  position: relative;
  display: flex;
  width: 680px;
  height: 40px;
  background-color: #fdf9f3;
  border-bottom: 1px solid #e0d9d7;
}

.weapon-box .nav li {
  width: 80px;
  height: 38px;
  margin-right: 20px;
  text-align: center;
  line-height: 38px;
  color: rgb(150, 131, 111);

  /* 2.2 bold: 700粗体 */
  font: bold 14px / 38px 宋体;

  cursor: pointer;
}

/* 2.3 设置默认活跃类名样式 */
.weapon-box .nav li.active {
  color: #ff610b;
}

/* 2.4 (定位)nav项下方游标样式 */
.weapon-box .nav .line {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 80px;
  height: 4px;
  background-color: #ff610b;

  /* (3.3同步)2.5 再加上过渡效果 */
  transition: all .5s;
}

/* 2.6 下方内容 */
.content {
  width: 680px;
  height: 152px;
  background-color: #fff;
}

.content .item {
  display: none;
  width: 680px;
  height: 152px;
  padding: 10px;
  color: #a862ea;
  font-style: italic;
  font-weight: 700;
}

.content .item.active {
  display: block;
}